Move error_code.h into otautil.

This way it stops requiring relative path ".." in LOCAL_C_INCLUDES
(uncrypt and edify). Soong doesn't accept non-local ".." in
"local_include_dirs".

Test: mmma bootable/recovery
Change-Id: Ia4649789cef2aaeb2785483660e9ea5a8b389c62
diff --git a/recovery.cpp b/recovery.cpp
index 4dc5b54..243ee4a 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -61,13 +61,13 @@
 #include "adb_install.h"
 #include "common.h"
 #include "device.h"
-#include "error_code.h"
 #include "fuse_sdcard_provider.h"
 #include "fuse_sideload.h"
 #include "install.h"
 #include "minadbd/minadbd.h"
 #include "minui/minui.h"
 #include "otautil/DirUtil.h"
+#include "otautil/error_code.h"
 #include "roots.h"
 #include "rotate_logs.h"
 #include "screen_ui.h"